Method of making deformed steel tubes



I Juni -1 0 1941.

' 2,245,421 A. VON FRANKENBERG UND LUDWIGSDORF EI'AL METHOD OF MAKING DEFORMED ST-EEL TUBES F'i1ed Nov. 25, 1938 pipes and the like.

' ess.

Patente d June 10, 1941 2,245,421 METHOD OF MAKING DEFORMED STEEL mns v Albrecht von Frankenberg und Llidwigsdorf und Heinrich Pro.iahn,- Gelsenkirchen, Germany,

assignors to United States Pipe Company, Burlington, N." J.

sind Foundry Applieation November 25, 1938, Serial N0. 242,384

In German'y Dek:ember 13, 1937 1 Claim. (Ol. 29-156) Scket pipes am] simllar holloW bodiies made of steel and with enlargements or reductions in cross-sectionai area er with thickened or recessed portions were hitherto produced almost without exception by first rolling a, continuous smooth walled pipe by means of sor'ne rolling process, am!

then producing, fpr example the sockets on the ends or any thickenings of the wa.ll thickness by widening upsetting or 12ressing.

When casting socket pipes and the 1ike an entirely difierent process is employed in that the sockets or thickened portions of the pipes are cast dire'ctly in the 'correspondihg casting process as is known for example in the upright ca.siw

ing prdcess and also in the centrifugal casiging process 'for the productin of cast-iron Socket Although'mz'.ny suggestions ha.ve been made for producing steel pipes also by the centrifugal casting process, such great difliculties h a.ve been enc ountered in carrying out these suggestions in pra ctice tha.t up to the present therhas been no real production cf steel pipes, steel Socket pipes or the like by the centrifugal castingproc- Thus, -for example it has been proposed to first cehtrifuge relatively thick-walled hollow blocks of lsteel and to then convert these centrifuged hollow blocks into their finaishape by subsequently reducing their wall thickness along the*ir entire length and 'over their entire crosssectional area. by rolling or drawlng, Inaccumcies iri the extern;al diamet er in the Wall thickness a.nd defects such as flaws in the outer sur-' face could be ignoied, because the centrifu ged interme'diate 'products were subsequently Subjected to a. roiling or dra.wing process all over. This me'thod of producing steel pipes 'is, ho weve r relatively complicated a.nd expensive.

Very recently it has been possible to progiuce the cent rifugal casting process satisf acto'ry stee1 pipes cpmplying with all requiremimts, true of their length. This is realised by' first pro-- 'fying (as compared the known centrifugal c'asting process for castiron Socket pipes.

I1; has, however, been f und that owing to the relatively great shrinkage cf the stee1 in solidiwith cast-iron) very fin e cracks easily occur at ti1e junctions between the pipe body and the pipe socket'and even in the socket itself owing to the greater quantities of materil at these points, which etacks may impair the appearance and the useflness cf the pipes, 1

Toeliminaiieihis possibilitygit is proposed, ac-

cording 130 the irivention, 110 produce steel socket pipes and similar hol low bodies. With enlargements 0r reductions in cross-sectzional anea er with thickened or recessed portions relatively short in a.xial directions, but, however, ofuniformcross-section along relatively lang sec tions ducing by the centrif u'gal qasting process the pipes o1 hollow bodies with su;bstantia.lly smooth continuous Wall surfacles possessing the final dross-sectional dimenion of their long part, of

uniform. cross-section whereupon only the. 500k- .et-like widened 'thickened er narrowed or similar portions necessary for the finished product are pr0duced in known manner by mechanical deformation, such as widening, forging; upsetting,

rolling or pressing, 1f ncessary utilizing the heat remaining in the products from the castipg "op- At the same time these semi-finished broducts' are centrifuged preferably in centrifugal moulds 130 mealsure and With fia.ultiess surfaces, by a.

special lin*lng in the. castixig' mould, which l-ining consists of 1oos ely introduced granular substances which vby corresp'ondingly high circumierential speed areheid togethet suflci(ei1tly tightiy to reiy. sha.peic6ntrifuglng moulds am). to cast the like directly the steel pipes sockets or Ehe during the centrlfugal casi sl ng procees,

steeiocket pipes are 'simwhich have a. centrifuged lining cf loosely introduced giamllar substances, whose lose coustitu enizs, during the in flowing of the casting material', are held together sufliciently tightly by the corre'spon'dingly high circumferential speed to resist washing away by the igilowing Jet of' Casti'ng material.

Accordixig to the new processit is possible for the flrst1time to produce in a. satisfactory mannex steel Socket pipes or slmilar hollow bodies hayingior example thickened or recessed portion5 or the like by the centrlfugal casting process, a

uniformly'*good quality of the product being ensured also on the socket portion or onthe thicki en'ed or narrowed vporion thereof owing to the subsequent formation only of the soclget or thickened or narr0wed portion or the like from the sp1ooth-bipe al ready centrifuged. to measure.

As an example of an application of ourinventiop, we wouk'i refer 1;0 the aceompanying drawing inwhidh Fig'ure 1 is a-longitudimil sgc'tion through the cexiter of a. centrifugal pipe casting machlne showing a, housing, a. rota.table mold mounted thereln, a motor and gearlng co'nnections Ior ro tating the mold, a trough supportegl from a movable carriage a.nd inserted within the mold, means for feeding malten metal to the trough a.r 1d means for tilting the trough, a. mold lining preferablj of loose granular material being also indicated as ls also somewhat diagrammatlcally indica.ted the cast steel tube.

Figure 2 is a transverse section on line 22 of Fig. 1, through the mold a.nd trough on an enlarged scale.

Ftigure 3 is a similar view to Fig. 2, showing the trough partially tilted and spllling malten metal into the mold.

Figure 4 is a, pgerspective view of 'a length o! pipe cast by the n'1echanism illustrated in Fig 1.

Figure 5 is a. longitudinal section.through the lenath of pipe shown' in Fig. 4, a.nd having a hell formed atone end thereof by expanding the end of the centrifugally cast pipe.

A is a. hou-sing, B a. cylindrical mold mounted on said housing, B an end fing.in the Iorm o1 a core located ab one end 01 the mold und. B a. metallic removable end ring lo zated at the other end of the mold. C indicates a. motor connected to rota.te the'mold through gearinz as lndicated' ad: C D, a robatable-trough Ior dellverlng molten metal to the mold. supported as shown by a,

mpv'able carriage D, means Ior tipping vthe trough being. diagrammatically indicat8d by the lever D*. E lndicates means Ior supplying the rota.table trough w1th molten metal. f indicates the lining. of the mold, F indicates the centri1'ugally ca.st steel tube or pipewhich, as cast, 1s

.of uniform diatn eter und uniform wall thickness and F Fix. 5, indicates the same tube or pipe having one end e'xpandedlnto the form o1 a hell or socket afte'r the pipe is withdrawn from the' mold.

; The operat ion is, o1 course, obvious, the cene fin'a.l dlmen8ions desired therefor.

trfiugal mold being in tevolutldn a.t a satlstactory speed 1or the pmbose, the molten steel is dumped lnto the rotating mold und centrifugally distributd over its sur1ace to form a. pipe or tube of uniform dla.meter und when the metal is set the pipe is withdrawn from the mold and such changes in its conf ormatlon as are desired are then brought bout as shown und, by way 01 'example, the only change noted is the expanslon of one end o1 the plpe to form a hell or socket.

A method of'manutacturlng steel tubes having to hold the granular pa.rticles making up the lining in flxed position against the washing efl5ect of the m 01ten metal, centrlfugally c'asting in the mold So llned a. steel tube wlth substantially smooth, continuous wall surtaces und 01 sub stanti-ally cyllndrlcal shape throughout its length and o! substantially uniform wall thlckness am! o1 mechanically deformable composition and structure, and then subjecting sald relatlvely sh0rt sectlon only o1 the cast tube while at su1table temperatures "to a. mechanlcal defoxmlng operatlon to impart thereto cross-sectlonal dimensions dittering 1rom those o! sald relatively long cylindrlcal section, seid rlatlv ely.long c?- lindrical seictlon belng esst to substantlglly the ALBRECHT (m FRANKENBERG m umwmsponn HEINRICH PROJAHN. 

